1. Field of the Invention
The present invention relates to a locking hinge assembly which can be set to hold a door in a predetermined position. More specifically, the locking hinge includes a sleeve containing an axially moveable hinge pin with a sprocket plate, that locks the hinge to maintain the door in specific position. The sleeve reduces the amount of slack in the hinge, thereby increasing the life of the hinge.
2. Description of the Related Art
Several different types of locking hinges have been disclosed in the prior art. None of the prior art devices, however, provide a hinge that: retains a door at any desired angle; permits adjustment of the amount of friction exhibited during opening and closing of the door; and has a sleeve for reducing slack and increasing the usable life of the hinge. The most pertinent prior art is the applicant's own U.S. Pat. No. 5,173,993, issued on Dec. 29, 1992. This patent discloses an adjustable locking door hinge that retains a door at any desired angle, permits adjustment of the amount of friction exhibited during opening and closing of the door, and operates in substantially the same manner as the present invention. Therefore, U.S. Pat. No. 5,173,993 is hereby incorporated by reference. U.S. Pat. No. 872,650, issued on Dec. 3, 1907 to Gilroy discloses a fluid operated locking hinge with an axially moveable hinge pin that locks the hinge in a closed position. U.S. Pat. No. 3,874,029, issued on Apr. 1, 1975 to McCullough discloses a locking hinge having an axially moveable hinge pin that locks the hinge in a several positions. U.S. Pat. No. 4,829,633, issued on May 16, 1989 to Kassner, shows a vehicle door hinge with an adjustable door check. U.S. Pat. No. 4,999,937, issued on Mar. 19, 1991 to Bechtold, teaches a panel sign having a ratchet hinge with an axially moveable hinge pin for engaging and disengaging the ratchet. U.S. Pat. No. 5,125,131, issued on Jun. 30, 1992 to Leblanc teaches a hinge locking mechanism with a fluid operated action. The entire device is disposed within a sleeve housing to form a cylinder and piston operating mechanism. U.S. Pat. No. 5,402,150, issued on Mar. 28, 1995, to Stiles shows a pointing device with a selectively lockable pivot. British Patent Specification No. 502,276, dated Mar. 15, 1939, shows a locking hinge assembly with an axially displaceable hinge pin. Italian Patent No. 552546, issued Dec. 6, 1956, shows a locking hinge assembly. The top portion of the hinge is fitted with a slotted aperture which operates in conjunction with a lock-engaging lever to lock the hinge in a plurality of positions.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus an adjustable locking hinge solving the aforementioned problems is desired.